A broke down has always been part of driving, so jack will be a necessity for a driver, when he or she meets some broke down issues.
It is applied for an invention patent on hydraulic electric Jack for vehicles (patent number: 200620357377.8), this kind of jack is composed of oil tank, motor, oil pump, piston push rod, which are connected with each other by complicated oil pipelines, in which valve cavity shall be added. The inside of the valve cavity is divided into two parts by steel ball-shape one-way valve, the upper valve cavity and the lower valve cavity. Inside the valve cavity is a movable object, on which there is one ejector rod used for pushing the steel ball. When the jack works, the rotation direction of the motor decides the flow direction of the hydraulic oil in the valve cavity in order to keep the piston ejector rod moving accordingly. While the jack is different to produce and assemble during its actual producing, assembling and using process, and its stability is not good as well. Investigating its reason, it is due to the complicated structure in the valve cavity and higher request for the position and movement relations between each component inside the valve cavity, as well as the complicated structure of the oil pipeline connected to the valve cavity. What's more, this kind of jack lacks of versatile functions, and can't be used for other purpose.